Snowmobiles, also known as snow sleds or sleds, snow bikes and other snow vehicles, particularly motorized personal snow vehicles for traveling across packed and unpacked snow, are well-known and well-characterized in the art. These vehicles are characterized by having one or more front skis and rear, endless, ground-engageable flexible drive tracks that support movement across snow-covered terrain. Unfortunately, the skis and drive track make it difficult to maneuver these snow vehicles on dry ground. This lack of ease of maneuverability makes moving, storing, and working on these vehicles cumbersome and even difficult. Particular issues include managing the weight and size of the vehicle and avoiding damaging a floor surface by contact with a vehicle's carbide skis. When mechanical repairs or maintenance is required, the vehicle needs to be elevated sufficiently and securely to allow stable and safe access to all parts of the vehicle.
A number of dollies, carts or lifting mechanisms are described in the art for lifting and transporting snow vehicles, particularly snowmobiles. Typically, the devices comprise wheels and some kind of pivoting or levering mechanism, often under the vehicle's center of gravity. Some devices require the snowmobile to be driven onto the dolly, others position the dolly under the vehicle and then lever the dolly to hoist the vehicle. The following patents are representative of the art:
U.S. Pat. No. 6,015,254 describes a centrally positioned levering device for lifting a snowmobile and balancing it in an elevated position as it is maneuvered about a surface. U.S. Pat. No. 6,869,087 describes a self-loading dolly onto which a snowmobile is driven. U.S. Pat. No. 5,716,061 describes a dolly positioned under the front portion of a snowmobile and comprising a jack for lifting the rear track portion off the ground. U.S. Pat. No. 5,441,378 describes a front positioning dolly rollably supported by casters and comprising a pivotable lifting lever. U.S. Pat. No. 3,860,078 and U.S. Pat. No. 4,288,087 each describe a front pair of ski supporting dollies and a rear supporting dolly or carriage.
None of the dollies or lifting devices described above are particularly adapted for secure, stationary, elevated access to a motorized snow vehicle, including a snowmobile, particularly for maintenance or repair applications to the rear drive track assembly. In addition, the lifting devices in the art that are adapted for snowmobiles are not readily adaptable or useful for lifting other motorized snow vehicles, such as motorized snow bikes. The state of the art for moving snow bikes across a dry surface is represented by Timbersled Products Inc.'s “All/Terrain Wheel Kit”, which comprises two laterally spaced wheel sets, one positioned under the front ski and secured by means of a rachet strap; the other positioned under the rear endless drive track. The kit is not designed to lift the rear assembly sufficiently or securely for maintenance applications. Moreover, the device is not adapted to keep its wheels from lifting off the ground when the vehicle is being moved or turned on a hard, dry surface, which can put the attached snow bike at risk of tipping over, especially while turning the bike or when moving the bike over unlevel surfaces. See, for example, http://www.timbersled.com/sbaccessories.htm.
There remains a need for simple, easy-to-use devices suitable for lifting and/or moving motorized snow vehicles that also provide stable and secure access to the vehicle for maintenance and repairs, and which also are adaptable and have utility for a range of snow vehicles, including snowmobiles and motorized snow bikes.